1. Technical Field
The present disclosure relates to digital shape modeling and, more specifically, to feature driven rule-based framework for automatic modeling of organic shapes in digital manufacturing.
2. Discussion of Related Art
Digital shape modeling is the process by which the shape of a device to be manufactured is designed with the assistance of computer aided design (CAD) software. After the desired shape is modeled in CAD software, the model file may be used in fabrication to produce a device with the desired shape. The use of digital shape modeling is widespread, however, when used for the modeling of organic shapes, such as in the field of medical prostheses, the complexity, irregularity and uncertainty of shapes can pose particular problems for digital shape modeling. One important example is the field of custom hearing aid manufacture.
A hearing aid is an electroacoustic device for the amplification of sound. Modern hearing aids may be worn either partially or fully within the ear canal. Examples of such hearing aids include in the canal (ITC), mini canal (MIC), and completely in the canal (CIC) aids. For these types of hearing aids, the entire hearing aid is designed to fit securely in the wearer's ear. To achieve this secure fit, the hearing aid is incorporated into an outer shell that is custom fitted to the shape of the wearer's ear canal.
Custom fitting of the hearing aid shell is accomplished by first taking an impression of the wearer's ear canal. This may be achieved by applying hardening foam or other molding substance into the ear of the wearer. Once removed and allowed to harden, the three-dimensional shape of the mold may be digitally scanned and imported into CAD software. Technicians may then perform various modifications and transformations to the three-dimensional image to convert the image of the wearer's ear into a model for fabricating the shell of a hearing aid. These image processing steps may be labor intensive, tedious and prone to error. These factors may then add to the cost and time required to produce a suitable hearing aid.